The ship's diesel-electric power plant consists of three 1,800-horsepower (1,300 kW) 10-cylinder 13D100 two-stroke opposed-piston diesel engines coupled to double-armature direct current (DC) generators.

[3][5] Having earned the nickname "Iron Pig" (German: Eisenschwein) over its 38-year service, Stephan Jantzen was replaced in 2005 by the icebreaking multipurpose vessel Arkona.

[8] In 2006, the icebreaker was acquired by the New York City-based businessman Paolo Zampolli who purchased it from the German state with the intention of rebuilding it to a luxury yacht for private voyages to the Arctic and the Antarctic.

[1][4] The icebreaker remained docked in Stralsund as the owner was reportedly unable to find a suitable shipyard to carry out the conversion work.

[3] In July 2012, Zampolli gave the association a week's notice to vacate Stephan Jantzen as the icebreaker would be leaving Rostock for conversion to a research ship.

[11] The ship was then reportedly sold to Kai Gunther Lehmann who registered it as a yacht in the Regensburg district court under the name König Ludwig II Von Bayern.